diff --git a/sys/include/net/dhcpv6/client.h b/sys/include/net/dhcpv6/client.h
index f836717283..36fc074a0f 100644
--- a/sys/include/net/dhcpv6/client.h
+++ b/sys/include/net/dhcpv6/client.h
@@ -54,6 +54,9 @@ extern "C" {
  */
 /**
  * @brief   Maximum number of prefix leases to be stored
+ *
+ *          Should be equal to the number of downstream interfaces
+ *          that are to be configured via DHCPv6
  */
 #ifndef CONFIG_DHCPV6_CLIENT_PFX_LEASE_MAX
 #define CONFIG_DHCPV6_CLIENT_PFX_LEASE_MAX (1U)